Effect of Ethanolamine as Capping Agent on ZnS Nanoparticles: Structural Characterization and Photo Degradation of Toxic Dyes

The high temperature wurtzite phase of ZnS was successfully obtained at low temperature (120°C) in the presence of ethynolamine (ENA) as the soft template. X-ray diffraction confirms the ENA-mediated phase transformation (zinc blende to wurtzite) of ZnS. UV-VIS spectra exhibits blue shift in all the samples. As the molar concentration of the capping agent increases, the absorption edge shifts to a lower wavelength. This blue shift of the absorption edges are evidence for different-sized ENA coated ZnS nanoparticles. In the present attempt, effects of phases and particle size of ZnS on photodegradation of dyes are systematically studied. Photodegradation of cango red, methylene blue, malachite green and dye waste collected from local industry, are systematically investigated by adding different molar proportional of ZnS in the dye. The rate of de-coloration of dye is detected by UV-VIS absorption spectroscopy. A significant reduction in the phase transition temperature and enhancement in photodegradation ability of ZnS has been achieved as compared to the bulk transition temperature (1020°C).